Polymers have frequently been used to thicken liquids. In strong acid solution, problems such as low viscosity yields, rapid viscosity deterioration, particularly at elevated temperatures, and precipitation of the polymer or their hydrolysis products through insolubilization or by multi-valent ion salts are encountered.
I have examined numerous compositions of acid and water containing water soluble polymers of both the natural and synthetic types. With the exception of the compositions containing the homopolymer or a salt of the homopolymer of 2-acrylamido-2-methylpropanesulfonic acid, I have not found any which did not suffer one or more of the above-mentioned problems in aqueous solutions having pH levels below about 2.